geocentric zenithSee zenith.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006
geocentric zenith[¦jē·ō¦sen·trik ′zē·nith]
The point where a line from the center of the earth through a point on its surface meets the celestial sphere.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.